I voted no. I can see the NSX as a legend, as it was developed with one of the most legendary F1 drivers, and it was just as fast, or faster, than some contemporary European sports cars. It boasted some neat technical features, like Ti conrods and Al monocoque chassis (wiki). And it didn't need mods to do any of that. Whereas the Supra, aside from its looks, only was famous for its ability to handle boost.

And the comment about JGTC cars... they barely represent actual their road-going brethren. Why do you think Racecar Engineering pretty much classifies them as prototype racecars?

I'd say Japanese legendary cars are the following, NSX, GT-R, Supra, the Japanese big 3! Of course there are other Japanese legend that deserve to be mentioned such as the Fairlady Z, Silvia, Evo, STI, RX-7.